Thermofan for GTV6

[Southern75]

Hi Guys,

I need to change a thermofan on a gtv6 as it has completely crapped itself with bits of brush and windings comming from within.

As the current fans seem to be a scarce commodity, what makes a suitable replacement?

I have looked at some of the davies craig thermofans and they look great as far as sizing an ease of fitting ... however i don't know what sort of limitations i have in terms of current available ir what sort of airflow i need in terms of CFM.

Can anybody advise me?

[Al Campbell]

Matthew,

I don't know about the Davies Craig, but I put a meter on my fan on the weekend. The one on the Drivers side (The A/C fan is missing on my car). It pulled 0.23A at 12.2V. That makes 2.8 watts. A little surprising, I would have thought it would be been a higher power than that, but it's a good quality meter.

As for available power, both the A/C fan and engine fan are powered through relays and the same 16A fuse (No. 3 on a 1983 GTV6). Nothing else is supplied through that fuse, so there's plenty of power available.

I know that people do replace the twin fans of the GVT6 with the single shrouded fan from the 75. The shroud makes the fan more efficient. They may do that for because original GTV6 fans are scarce. Also I was buying some parts from a bloke a few months ago who had a radiator for sale that had two fans from Magna's fitted.

I've been driving my car in the recent heat and watching the temperature gauge and the single fan seems to work o.k., even when stationary. So if no one with more experience comes up with any facts about what works or what they've done, if your radiator and water pump are in good condition I think you would be alright with whatever you can fit. Electric motors and fans won't have changed much since these cars were made.

Certainly this would be the time of year to test things out.

Let us know what you do and how it works.

AL.

P.S edit: Davies Craig list their smallest fan as pulling 5A at 12v, which is more like what I would expect. I measured the current at the thermo sensor because that was the easiest to access. I've checked the circuit diagram three times now and it does show the sensor as supplying the fan directly, but I have found errors in the past. 0.23A sounds more like a relay triggering current. I'll check the fan current agin, measuring right at the fan.

[Al Campbell]

I got to listen to those nagging doubts, especially before shooting my mouth off online. I put a meter on the fan motor itself, it draws 7.6 A with the car idling. So what I measured across the sensor must have been a relay energising current (despite what the circuit diagram shows).

I had a look in the electrical chapter of the 75/GTV6 manual (from Craig's Place) and couldn't find any specs on cooling fans.

I'm guessing a Davies Craig fan rated at 7A maximum current (DCSL10) wouldn't be less efficient than the old ALFA one.

If you wanted to use two fns that drew a total of greater than 16A, you could put in another relay and fuse for one fan.

AL.

[Southern75]

Hi Al

Thanks for your efforts.

The Davies craig fans i was looking as were rated at 9A which i though it should cope with ... esp if i ran another relay.

They did have some 7.5A one which also sounded ok

I heard of fitting 156v6 fans which work well but apparently draw a lot .. too much for the alternator to cope with ... but it does cool very quickly and it nearly sucks you through the grille